Traditionally, the vertical flight of an aircraft (such as a helicopter) has been controlled using a trunnion that provides for collective control in the aircraft. For example, the trunnion may slide up and down a helicopter's drive tube so that the angle of each of the helicopter rotor blades may be changed simultaneously. This may increase or decrease the lift provided to the helicopter, thereby increasing or decreasing the altitude of the helicopter. These prior art trunnion systems, however, have disadvantageous which may be addressed in this disclosure.